Select several very large onions, wipe them without peeling, and drop them into boiling water for several minutes. Remove and let cool. Cut off the top and carefully scoop out the interior with a knife, leaving the outer wall intact. Add 5–6 more peeled, [raw] onions to the onion pulp removed from the interior. Cut up or finely chop all the onions together, pour the chopped onions into a saucepan, add ¾ glass cream, and boil until they are as soft as kasha. Rub through a sieve. Remove a fillet from a large young chicken, scrape it with a knife, and pound in a mortar. Add 4 eggs, ½ lb melted butter, 4 finely chopped sprats, a little grated cheese, a French roll (without the crust) soaked in milk and squeezed out, and a little salt and pepper. Add the onion purée, mix everything thoroughly, and fill the prepared onion shells.
After this, prepare short pastry, roll it out as thin as possible, and cut it into rectangles with a cutting wheel. Place a stuffed onion in the middle of each rectangle and fold up the four comers of dough to form four leaves, as it were, on top. Pinch the leaves together tightly in the middle and paint the sides with egg white, using a feather. Let them dry slightly and bake in a saucepan or small basin with fat, Russian butter, or half fat and half Russian butter.
Serve at the table with the following cream sauce. Melt 1 spoon butter in a saucepan, mix with 1 spoon flour, and dilute with 1½ glasses cream. Add a little salt, pepper, and, if desired, the juice of ½ lemon. Boil thoroughly and serve in a sauceboat.